diff --git a/src/xenia/kernel/util/xex2.cc b/src/xenia/kernel/util/xex2.cc
index ab8d594e4..3eccb68cf 100644
--- a/src/xenia/kernel/util/xex2.cc
+++ b/src/xenia/kernel/util/xex2.cc
@@ -27,6 +27,34 @@
 #include "xenia/base/memory.h"
 #include "xenia/base/platform.h"
 
+namespace xe {
+namespace kernel {
+template <typename T>
+T* xex2_get_opt_header(const xex2_header* header, uint32_t key) {
+  for (int i = 0; i < header->header_count; i++) {
+    const xex2_opt_header* opt_header = header->headers[i];
+    if (opt_header->key != key) {
+      continue;
+    }
+
+    if ((opt_header->key & 0xFF) == 0x01) {
+      // Data is stored in the opt header
+      return (T*)&opt_header->value;
+    } else {
+      // Data stored at offset.
+      return (T*)((uint8_t*)&header->headers[0] + opt_header->offset);
+    }
+  }
+
+  return nullptr;
+}
+
+uint32_t xex2_get_header_size(const xex2_header* header) {
+  return header->exe_offset;
+}
+}  // namespace kernel
+}  // namespace xe
+
 // TODO(benvanik): remove.
 #define XEEXPECTZERO(expr) \
   if ((expr) != 0) {       \
@@ -126,7 +154,7 @@ int xe_xex2_read_header(const uint8_t *addr, const size_t length,
   xe_xex2_loader_info_t *ldr;
 
   header->xex2 = xe::load_and_swap<uint32_t>(p + 0x00);
-  if (header->xex2 != 0x58455832) {
+  if (header->xex2 != 'XEX2') {
     return 1;
   }
 
@@ -356,8 +384,8 @@ int xe_xex2_read_header(const uint8_t *addr, const size_t length,
             uint32_t window_size = xe::load_and_swap<uint32_t>(pp + 0x08);
             uint32_t window_bits = 0;
             for (size_t m = 0; m < 32; m++, window_bits++) {
-              window_size <<= 1;
-              if (window_size == 0x80000000) {
+              window_size >>= 1;
+              if (window_size == 0x00000000) {
                 break;
               }
             }
diff --git a/src/xenia/kernel/util/xex2.h b/src/xenia/kernel/util/xex2.h
index c2c808c6e..536781ceb 100644
--- a/src/xenia/kernel/util/xex2.h
+++ b/src/xenia/kernel/util/xex2.h
@@ -13,6 +13,15 @@
 #include "xenia/kernel/util/xex2_info.h"
 #include "xenia/memory.h"
 
+namespace xe {
+namespace kernel {
+template<typename T>
+T* xex2_get_opt_header(const xex2_header* header, uint32_t key);
+
+uint32_t xex2_get_header_size(const xex2_header* header);
+} // namespace kernel
+} // namespace xe
+
 typedef struct { int reserved; } xe_xex2_options_t;
 
 struct xe_xex2;
diff --git a/src/xenia/kernel/util/xex2_info.h b/src/xenia/kernel/util/xex2_info.h
index f3a467f46..fa1281935 100644
--- a/src/xenia/kernel/util/xex2_info.h
+++ b/src/xenia/kernel/util/xex2_info.h
@@ -12,6 +12,8 @@
 
 #include <cstdint>
 
+#include "xenia/base/byte_order.h"
+
 typedef enum {
   XEX_HEADER_RESOURCE_INFO = 0x000002FF,
   XEX_HEADER_FILE_FORMAT_INFO = 0x000003FF,
@@ -467,4 +469,56 @@ typedef struct {
   xe_xex2_section_t* sections;
 } xe_xex2_header_t;
 
+namespace xe {
+namespace kernel {
+union xex2_version {
+  uint32_t value;
+  struct {
+    uint32_t major : 4;
+    uint32_t minor : 4;
+    uint32_t build : 16;
+    uint32_t qfe : 8;
+  };
+};
+
+struct xex2_opt_execution_info {
+  xe::be<uint32_t> media_id;          // 0x0
+  xe::be<xex2_version> version;       // 0x4
+  xe::be<xex2_version> base_version;  // 0x8
+  xe::be<uint32_t> title_id;          // 0xC
+  uint8_t platform;                   // 0x10
+  uint8_t executable_table;           // 0x11
+  uint8_t disc_number;                // 0x12
+  uint8_t disc_count;                 // 0x13
+  xe::be<uint32_t> savegame_id;       // 0x14
+};
+
+struct xex2_opt_header {
+  xe::be<uint32_t> key;  // 0x0
+
+  union {
+    xe::be<uint32_t> value;   // 0x4
+    xe::be<uint32_t> offset;  // 0x8
+  };
+};
+
+struct xex2_header {
+  xe::be<uint32_t> magic;                     // 0x0 'XEX2'
+  xe::be<xe_xex2_module_flags> module_flags;  // 0x4
+  xe::be<uint32_t> exe_offset;                // 0x8
+  xe::be<uint32_t> reserved;                  // 0xC
+  xe::be<uint32_t> certificate_offset;        // 0x10
+  xe::be<uint32_t> header_count;              // 0x14
+
+  xex2_opt_header headers[1];  // 0x18
+};
+
+struct xex2_loader_info {
+  xe::be<uint32_t> header_size;
+  xe::be<uint32_t> image_size;
+
+};
+} // namespace kernel
+} // namespace xe
+
 #endif  // XENIA_KERNEL_XEX2_INFO_H_